Convenient All-In-One Precise Heat Mat Best Seller! Easy to set up, the adjustable controller is built right into these mats! Simply unroll the mat, place your flats on it, place the copper probe in the soil, plug it in and grow. Adjust the temperature from 40 to 100 °F, for best growth. The heat mat material is the same high quality plastic, sealed against moisture, that is used in all of the Agritape mats.